The present invention relates to patient-support devices, and particularly, to infant thermal support devices of the type having a humidity controlled environment for a patient supported by the device. More particularly, the present invention relates to a self-contained humidifier module that is inserted into a patient-support apparatus.
It is conventional to humidify the air which is circulated inside an infant incubator. Conventional incubators, or patient thermal support devices as they are known, have systems for recirculating warmed air in the environment in which the infant resides. The environment may be enclosed by some type of housing or canopy over a support or the environment may be a space which is controlled by one or more curtains of heated air. The objective is to provide controlled humidity in the environment by adding moisture to the heated air. It is desirable to humidify the air so that evaporative heat losses from a patient exposed to the humidified air are minimized. See, for example, U.S. Pat. Nos. 5,224,923 and 5,336,156 showing humidifiers associated with infant incubators.
The present invention is a humidifier module for a patient-support apparatus including an opening into which the module is inserted, an electrical service connector, an air inlet port, and an air outlet port. The humidifier module, which is to be inserted into the patient-support apparatus, comprises a water reservoir for holding water, a heater for heating the water, an air chamber with an air inlet port and an air exhaust port for mating with the air inlet and outlet ports of the support apparatus, and an electrical connector for mating with the electrical service connector of the patient-support apparatus. The patient-support apparatus is provided with a humidified environment for the patient when the humidifier module is inserted into the opening of the patient-support apparatus.
The patient-support apparatus may include one or more external doors that normally close the opening of the patient-support apparatus. The external doors are opened by the insertion of the humidifier module through the opening of the patient support apparatus. The patient-support apparatus may also include one or more internal doors that normally close the air inlet and outlet ports of the patient-support apparatus. The internal doors are opened by the insertion of the humidifier module through the opening and into the patient-support apparatus.
The humidifier module may include one or more spill damper doors that close the air inlet port and air exhaust port of the humidifier module to prevent hot water heated by the heater from spilling out of the humidifier module when the humidifier module is removed from the patient-support apparatus. The patient-support apparatus may include door opener tabs that engage and open the spill damper doors when the humidifier module is inserted into the patient-support apparatus. In preferred embodiments, the humidifier module includes a pair of door openers that are positioned beneath the respective air inlet and exhaust ports and each door opener is formed to include a recess that catches any water that inadvertently spills out of the humidifier module through the air inlet and exhaust ports.
In the preferred embodiments, a substantial portion of each of the water reservoir, the heater, and the air chamber pass through the opening of the patient-support apparatus as the humidifier module is inserted into the apparatus. The humidifier module can include a refill door that is positioned to lie outside a compartment of the patient-support apparatus in which the humidifier module is received. The refill door can be opened so that water can be poured into the water reservoir without having to remove the humidifier module from the patient-support apparatus.
It will be appreciated, therefore, that the patient-support apparatus of the present invention comprises a compartment for accepting a removable self-contained humidifier module, an air inlet in fluid communication with the compartment, an air outlet in fluid communication with the compartment, and an electrical service connector positioned to lie in the compartment. The humidifier module includes a water heater chamber and cooperating inlets and outlets for connecting with the air inlets and outlets of the patient-support when the humidifier module is inserted into the compartment. The humidifier module further includes an electrical connector that couples to the electrical service connector of the patient-support apparatus and a heater coupled to the electrical connector. In preferred embodiments, the electrical connector of the humidifier module aligns with and automatically connects to the electrical service connector of the patient-support apparatus when the humidifier module is inserted into the patient-support apparatus.
Thus, there is provided a patient-support apparatus having a patient support and a fluid circulation system with a flow path that directs circulated fluid through the patient support to provide a thermally controlled environment for a patient. The patient support includes a compartment for accepting a removable self-contained humidifier module, an inlet port in fluid communication with the compartment and an outlet port in fluid communication with the compartment. The apparatus also includes a first door pivotably coupled to the patient support and normally closing the inlet port, a second door pivotably coupled to the patient support and normally closing the outlet port. The humidifier module includes a water container for containing water, an inlet port for connecting with the outlet port of the patient-support when the humidifier module is inserted into the compartment, an exhaust port for connecting with the inlet port of the patient-support when the humidifier module is inserted into the compartment, and first and second door openers arranged to engage and pivot the respective first and second doors to an open position to allow at least some to the fluid in the first path to be diverted through the humidifier module and over the water contained in the water container.
The preferred humidifier module of the present invention comprises a container for holding water and an air chamber above the water. The container may have an air inlet port and an air exhaust port providing for air flow movement through the chamber. The humidifier module includes a heater for heating the water and a water reservoir for holding additional water. The humidifier further includes a control valve coupled to the water reservoir and coupled to the container. The control valve has a closed configuration blocking the flow of water from the water reservoir to the container and the control valve has an opened configuration allowing the flow of water from the water reservoir to the container. A level sensor senses the water level in the container and provides a signal to the control valve to move the control valve between the opened and closed configurations.
For safety reasons, the preferred humidifier module comprises a locking mechanism that locks the humidifier module to the patient support of the patient-support apparatus when a temperature sensor, which is coupled to the locking mechanism, senses a temperature that exceeds a predetermined temperature. The locking mechanism includes a locking post and a solenoid that extends the locking post to a locking position and that retracts the locking post to a releasing position depending upon the temperature sensed by the temperature sensor. The patient-support apparatus is formed to include an aperture that receives the locking post when the locking post extends to the locking position.
In accordance with present invention, the patient-support apparatus comprises a patient support having a first chamber, a second chamber and a fluid-flow orifice between the first and second chambers. A fan is positioned to lie in the first chamber. The fan is operable to move fluid through the orifice into the second chamber. A laminar flow profile structure is appended to the patient support in the second chamber and configured to maintain laminar flow of the fluid as the fluid enters the second chamber from the first chamber. The patient support is formed to include at least one flow aperture in fluid communication with the second chamber and the fluid flows from the second chamber through the aperture to an area surrounding a patient supported on the patient support.
In preferred embodiments, the patient support includes a platform tub and a platform cover positioned to lie above a channel formed in the platform tub. The platform cover is formed to include a mattress-receiving aperture and a plurality of vent slots that are arranged around the mattress-receiving aperture. The vent slots are in fluid communication with the channel so that some of the fluid flowing in the channel passes upwardly through each of the vent slots. The patient support further includes a bottom wall having a datum surface in the first chamber and inclined surfaces in the channel. The inclined surfaces are configured so that air exits each vent slot of the platform cover at substantially the same velocity.
Additional features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.